US2862706A - Cinematographic film brake - Google Patents

Description

Dec. 2, 1958 B. TUCKER 2,862,706

CINEMATOGR'APHIC FILM BRAKE Filed Junev 7, 1955 .9: s a; g 26 \5 Japan/02 71 51150270 ,3 Twi jy%w% *M Jiffy/f United States Patent" ClNEMATOGRAPHIC FILM BRAKE William B. Tucker, Los Angeles, Calif., assignor to Technifcolor Corporation, Hollywood, Calif., a corporation 0 Maine Application June 7, 1955, Serial No. 513,703

Claims. (Cl. 2712.3)

In a cinematographic machine it is often desirable to brake a film so as to retard its travel or stop it quickly. However if a film is retarded quickly, there is a tendency for it to jump off its guide rollers.

Objects of the present invention are to provide a brake which is simple and economical in construction, which can be applied quickly without injury to the film or danger of the film jumping off its guide rollers, and which is durable and reliable in use.

According to the present invention the apparatus comprises a roller over which the film travels throughout an are extending around one side of the roller from the location where the film meets the roller to the location where it leaves the roller, together with a brake associated with the roller for retarding the film travel, a presser for pressing the film against the roller between the two locations, and means for actuating the presser and brake concomitantly so that the film remains in position on the roller while being braked. Preferably the presser is near the location where the film meets the roller and the brake is located farther along the aforesaid arc. In the preferred embodiment the presser is applied first, followed by the application of the brake. Preferably the means for concomitantly actuating the brake and presser includes a spring interposed between the brake and presser to apply yielding pressure to the presser after it reaches the roller, the pressure gradually building up until the brake reaches the roller.

For the puipose of illustration a typical embodiment of the invention is shown in the accompanying drawings in which Fig. l is a side elevation;

Fig. 2 is a section on line 22 of Fig. 1;

Fig. 3 is a section on line 3--3 of Fig. 1; and

Fig. 4 is a section on line 44 of Fig. 1.

In the illustration the film F is guided along a predetermined path by means of rollers 1 and 2, the film traveling along the roller 2 throughout an are beginning at 3 and ending at 4. Associated with the roller 2 near the end of this are is a brake comprising shoes 6 mounted on an arm 7 by means of screws 8, the arm being pivoted on a pin 9 so that the brake can be moved toward and from the roller. As shown in Fig. 3 the roller 2 has the usual flanges 11 and, immediately inside the flanges,v

shoulders 12 upon which the margins of the film rest with the central picture-carrying zone of the film spaced from the roller. The brake shoes comprise plates on opposite sides of the arms 7 which engage the film only throughout the width of the shoulders 12, the plates being shaped to fit the contour of the film on the roller when the brake is applied.

In the illustrated embodiment the brake is applied by a plunger 13 actuated by an air cylinder 14 controlled in any suitable way, as for example as disclosed in the copending application of Malcolm H. Ames and William B. Tucker, Ser. No. 495,532, filed March 21, 1955, now Patent No. 2,809,828, issue of Oct. 15, 1957.

2,862,706 Patented Dec. 2,. .1958

To keep the film from jumping off the roller v.2 when the brake is applied,.a presser roller or presser 16 is arranged to engage the film at the beginning of the afore-v said arc. As shown in Fig. 2 the roller 16 has marginal flanges 17 which press the film against the shoulders 12. on the roller 2 throughout the width of the shoulders. The roller 16 is mounted on a shaft carrying roller bearings 18 on its ends, the bearings being mounted in forked arms 19 pivotally mounted at 21. The arms 19 have lateral extensions at their upper ends which are interconnected with the arm 7 through a link 22, the link sliding in a pin 25 pivotally mounted on arm 7. The spring 23 is disposed between the pin 25 and a head 26 on the lower end of the link. A stop 27 is mounted on the link above the pin 25..

Normally the parts occupy the position shown in Fig. l with the presser roll 16 retracted a short distance from the roller 2 and the brake 6 retracted a somewhat greater distance. Thus when air is admitted into the cylinder 14 the plunger 13 swings the arm 7 in a counterclockwise direction around pin 9, causing arm 19 to swing in a counterclockwise direction around pivot 21 until the presser roller 16 contacts the film. Continued movement of the arm 7 compresses spring 23 until the brakes 6 contact the film. Thus presser roller 16 is pressed yieldingly against the film in advance of the brake so that the film may be retarded quickly without danger of it jumping off the roller 2.

It should be understood that the present disclosure is for the purpose of illustration only and that this invention includes all modifications and equivalents which fall within the scope of the appended claims.

I claim:

1. Cinematographic apparatus comprising a roller over which film travels throughout an are extending around one side of the roller from the location where the film meets the roller to the location where it leaves the roller, a brake associated with the roller for retarding the film travel, a presser for pressing the film against the roller between said locations, and means for concomitantly operating the presser first and then the brake, thereby to hold the film in position on the roller while being braked.

2. Cinematographic apparatus comprising a roller over which film travels throughout an are extending around one side of the roller from the location where the film meets the roller to the location where it leaves the roller, a brake associated with the roller for retarding the film travel, a presser for pressing the film against the roller between said locations near said first location, and means for concomitantly operating the presser first and then the brake, thereby to hold the film in position on the roller while being braked.

3. cinematographic apparatus comprising a guide roller over which film travels throughout an are extending around one side of the roller, a brake on the side of the film opposite the roller for pressing the film against said roller at one location along said arc, a presser roller for pressing the film against said roller at another location along said arc in advance of said first location, and means for actuating the presser roller and brake concomitantly, thereby to hold the film in position on the roller while being braked.

4. cinematographic apparatus comprising a guide roller over which film travels throughout an are extending around one side of the roller, a brake for pressing the film against said roller at one location along said arc, a presser roller for pressing the film against said roller at another location along said are in advance of said first location, and means for concomitantly operating the presser first and then the brake, thereby to hold the film in position on the roller while being braked.

3 r V V 5. Cinematographic apparatus comprising a guide roller over which film travels throughout an are extending around one side of the roller, a brake for pressing the film against said roller at one location along said arc, a presser roller for pressing the film against said roller at another location along said are in advance of said first location, and means for concomitantly moving the brake and presser toward the roller so that the resser reaches the roller first, said means including a spring interposed between the brake and presser to apply yielding pressure to the presser after it reaches the roller, thereby to hold the film in position on the roller while being braked.

References Cited in the file of this patent UNITED STATES PATENTS 1,912,013 Schneider May 30, 1933

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